The US Congress yesterday gave final approval to a $48bn White House-backed plan to fight HIV/Aids and malaria in the developing world, with conservatives failing to rally support for a smaller prevention programme.

The Aids bill ends a requirement that one-third of US contributions to the UN's global fund for HIV/Aids, tuberculosis, and malaria be spent on the exclusive promotion of sexual abstinence.

The new plan, expected to receive George Bush's signature within days, also removes the US prohibition on granting visas to HIV-positive foreigners, a long-standing priority of gay-rights groups.

"In the face of the Aids pandemic, this bill will show the world, unambiguously, that America accepts its obligation to act," Steny Hoyer, the Democratic majority leader of the House of Representatives, said in a statement.

While yesterday's vote authorises future Aids and malaria spending, a separate bill must be passed to free up the money. A recent study by the non-profit Kaiser Family Foundation found that during 2005 and 2006, the US only gave out about 60% of the money it had authorised.

Bush had pressed Congress to authorise the $48bn before his arrival at the G8 summit in Japan earlier this month, but conservatives from the president's party stalled the plan out of opposition to the spending increase. Republican senators also fought unsuccessfully for restrictions on giving money to overseas aid groups that promote abortion.